The present proposal continues the ongoing efforts of this investigator to elucidate the biological effects of beta 1,4-galactosyltransferase (Gal Tase), and the expression of GTA-K on acinar cell growth response. The following specific aims have been proposed: (1) Elucidate the chromosomal structure of the GTA-K and determine the role of the regulatory sequences in the expression of this protein. (2) To study the biological effects of the GTA-K through site-directed mutagenesis of various functional domains. It is anticipated that these studies will provide new information about one possible mechanism involved in the regulation of acinar cell growth. A model which has been widely used, for almost three decades, to study acinar cell growth is the acinar cell proliferation in response to beta adrenergic stimulation. This study is aimed towards further characterizing the mechanisms associated with this proliferative event.